1. Field of the Invention
This invention relates to the field of roadway traffic barriers.
2. Prior Art
Traffic barriers are well known for use on roads as a boundary for traffic lanes. These traffic barriers have been in the past made of concrete and either cast in place or been prefabricated. These barriers may have a height comparable to the normal tire size of a passenger vehicle and may also be slightly higher. The barriers normally have a wise supporting base and extend upwardly in a trapezoidal shape to approximately half the height of the barrier. The side faces of the barrier then extend upwardly through a steeper slope forming the narrow head portion. These curves and slope faces have the function of reflecting a vehicle driven against the barrier back into the lane of traffic. These barriers may have an average height of approximately 85 cm. In some cases, in order to save material, only one side of the barrier has the foregoing shape while the backface opposite to the lane of traffic may be formed without the lower slope face.
It has been known to interlock such prefabricated concrete barriers by pouring concrete into the joints between the vertical end faces. Upon impact by a vehicle on one barrier, the tension forces are transferred to adjacent rigidly interlocked barriers. However, such rigid interlocking has the disadvantage of requiring poured in place concrete at the site. Filling the voids between the vertical end faces may take a considerable amount of time. Rigid interlocking has been found objectionable in that after a traffic accident in which the barriers are damaged, replacing the barriers may require expensive and time consuming procedures. Such procedures require a partial destruction of the barrier system.
As a substitute for the foregoing rigid interlocking system, it has been known to provide both ends of a prefabricated concrete barrier with hinge discs as described, for example, in German Pat. No. 1266785. In this system a hole matching a hinge disc is coupled to a hole attached to the top of a support to which the barriers are attached using bolts and nuts through the centered holes in the hinge discs. However, this system is objectionable when using the concrete barriers described above since the joints between barriers would be far too large. In addition, the bolts would be required to be oversized to transfer required amounts of tension forces between adjacent barriers when a barrier is impacted by a vehicle.